The man who murdered Sarah Payne has had his 50-year jail term reduced by the high court in London.

Roy Whiting was jailed for life after being convicted of Sarah's murder in 2001, and was ordered to serve a minimum of 50 years in prison by David Blunkett, who was home secretary.

That has been reduced to 40 years after he successfully appealed the sentence.

Sarah's mother, Sara Payne, who was in court to hear the verdict, said she was "disappointed" but had been prepared for a reduced sentence.

Whiting, 51, kidnapped and killed Sarah Payne in July 2000. He was not present to hear Mr Justice Simon announce his decision on the time allowed to pass before a parole application.

In 2002 Blunkett ruled that Whiting must serve 50 years before becoming eligible to apply for parole. But Simon said he had concluded that the "appropriate" minimum term was a period of 40 years. He stressed the sentence on Whiting remained one of imprisonment for life.

The judge said he would be detained "unless and until the parole board is satisfied that he no longer presents a risk to the public".

"Even if the parole board decides then or at some time in the future to authorise his release, he will be on licence for the rest of his life," Simon said.

Speaking outside court, Sara Payne, accompanied by her children Lee, 23, Luke, 21, and 15-year-old Charlotte, said: "The family is clearly disappointed that the tariff has been reduced, but he will be well into his 80s before he is eligible, so it's not a terrible, terrible thing, and could have been a lot worse, so we carry on as before.

"He's in prison now, he can't hurt any children there."

Payne said she would continue campaigning for "a safer Britain for children" despite falling seriously ill last year.

After announcing the new minimum term, the judge said: "I invite everyone present in court, before we go about our daily business, to pause and for a moment remember Sarah Payne who would now be 18 if she had not been murdered, and reflect the grave loss her death has caused to her family and others who loved her."

This morning Payne told GMTV the 10th anniversary of her daughter's murder this July would be "awful" but said "her birthday [in October] is worse for me".

Appearing on the programme ahead of the appeal ruling, Payne said it made her "really mad" that prisoners continued to have "legally aided fights". "What we would like to see is a much more fair system where victims can have as much access to legal aid as prisoners," she said.

"Obviously it is law firms, lawyers, that go round and tell prisoners 'Did you know you could be fighting on this, or this, or this?' and of course prisoners want to buck the system as much as they can."